Code Design - aeg7aeg7.com/assets/spa/07-code design.pdf · thesis is a negotiation between the cultural landscape and the economics of development. The code test, which I designed

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Code Design

The starting point is that the most permanent and enduring elements of cities are often related to the underlying landscapes—the geology, the topography, the rivers and harbors, and the climate. This does not mean a denial of the realities of globalization or the influence of technology, but recognition of the importance of place and its connection to natural systems (Mossop 2006, 172).

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The attention required to craft a code that crosses jurisdictions and public/private boundaries

requires a significant amount of attention to be paid to a specific place. Perhaps, this is exactly

what the neglected “gray area” urban arterial needs to face the challenge of sustainable urbanism.

The Urban Ecotone Code proposes five to six development typologies for the private realm

along San Pablo Avenue, incorporating the existing building stock and land uses, into the code.

The following elements create a framework for the layout of the development types, linking

the public realm to the private: The hydrological infrastructure of creeks and culverts, the

rolling topography of the watersheds, neighborhood centers, and transit-oriented centers. The

existing cultural landscape plays a large role in the design of the Urban Ecotone Code.

Designing the Urban Ecotone Code

The Urban Ecotone Code presents a holistic code for all of the jurisdictions involved in the

planning and design of the urban arterial by implementing concepts from form-based codes

and performance-based codes. The Urban Ecotone Code is split into two parts: the private

realm of parcel development and the public realm, including the connective infrastructure.

To refine the private/parcel design of the Urban Ecotone Code, architects and landscape

architects from across the country and the world, admittedly good friends of mine, performed

code tests by designing proposals according to the code for individual parcels along the corridor

within the 5-mile strip. This chapter consists of a presentation and explanation of the code.

The following chapter presents the results and findings from the returned code tests.

TOPOGRAPHY HYDROLOGY COMMUNITY Local & Regional

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Following the basic format of a form-based code, the Urban Ecotone Code contains a

regulating plan, design typologies, and an administrative text. The following form and

performance standards were also included to support the urban ecotone concept: block and

parcel standards, building frontage and massing standards, open space standards, sunlight

standards, fresh air/ventilation standards, food security/production standards, alternative

energy production standards, decentralized infrastructure standards, Leadership in Energy and

Environmental Design (LEED) and Sustainable Sites Initiative (SSI) performance standards,

on-site stormwater/rainwater harvesting standards, parking standards, on-site vegetation

standards, and riparian and drainage area standards. A checklist was added as an evaluation

tool as well as a concise way of understanding the code requirements and their applicability to

the individual parcels. The idea for a checklist as well as some graphic inspiration came from

Chan Krieger Sieniewicz’s form-based code for the South Knoxville Waterfront, as illustrated

in the analysis chapter. (I tested the Knoxville code while working at the firm, and this memory

is what prompted me to seek others to test the Urban Ecotone Code.)

Regulating Plan and Development Types

The regulating plan was assembled from a wide pool of information. Initially, four types of

development conditions were identified based on information taken from the ABAG Focus

Initiative and the San Pablo Avenue Specific Plan. The ABAG Focus Initiative identified the

two BART stations, within the 5-mile strip, as priority transit development areas, where a

high intensity of uses and densities should be developed. The ABAG Focus Initiative identifies

these areas for the entire corridor based on BART and AMTRAK stations, for a total of five

areas of transit-oriented development. Specific to the two BART stations in the 5-mile strip,

the availability/vacancy and large size of the parcels in these two zones also facilitates the

transit-oriented development typology. On the regulating plan, these areas are labeled as SPA4.

(Each development area also has an individual graphic and text description, which explains the

specific requirements for that type. These will be elaborated upon later in this chapter.)

138Urban Ecotone Code Regulating Plan

REGULATING PLAN & DEVELOPMENT TYPOLOGIES

Fairmount AveCentral Ave

Moeser Lane

Solano Ave

I-80I-580

Potrero Ave

Cutting Blvd

Macdonald Ave

Barrett Ave

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Urban Ecotone Code Development Type SPA 4

The next development type, SPA3 was determined by the designation of neighborhood

commercial centers and/or civic centers in the San Pablo Avenue Specific Plan for the cities

of El Cerrito and the adjacent areas of Richmond. All of the cities along San Pablo Avenue

designate similar areas in their General Plans, which makes this a typical condition spaced

intermittently along the corridor. SPA3 also serves as transitional building intensity between

the transit-oriented intensity of SPA4 and the typical condition intensity of SPA2. Admittedly,

this thesis subscribes to the urban design rubric of legibility, and therefore, the neighborhood

centers where there is a greater mixing of people and uses, reads as differentiated from the

typical development condition. Stated in terms of ecology, SPA4 and SPA3 are patches of

increased diversity, while SPA2 and SPA1 facilitate movement along and across the corridor;

all of them contributing to the edge effect otherwise known as connectivity and permeability

of a place.

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Although SPA2 is described as the typical condition, it allows for enough variety of form that

it should not produce monotonous or homogenous spaces. It is worth pointing out that the

existing fabric contributed significantly to the design of this code, so that the transformation

of San Pablo Avenue could retain aspects of its cultural landscape, including the buildings.

The code accepts and celebrates the fact that not all of the parcels will transform to the code’s

delineation. Even if only half of the parcels with parking lots fronting San Pablo Avenue

were to be redeveloped according to the Urban Ecotone Code, the transformation could shift

perceptions from an auto-oriented strip, to an ecotone destination for pedestrians.

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SPA1 was created as a special condition to protect viewsheds to and from existing topography.

The height limit is based on existing buildings, feedback from citizens participating in the San

Pablo Avenue Specific Plan and meetings with members of the Richmond Annex Neighborhood

Association. The development types SPA1-3 all address transitions at the rear property line

to the adjacent single-family detached residential land use to mitigate for sunlight and noise

issues. The numerous accessory dwelling units present in these residential areas discounted

privacy issues concerning views into back yards, since they are a shared space. SPA4 areas are

self-contained districts enclosed by infrastructure landscapes. New blocks and parcels have

to be designated in SPA4 and are not adjacent to residential land uses, so the rear property

conditions reflect this difference.

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If this regulating plan were to be applied to the entire corridor, there would need to be at least

one more development type: a higher intensity type for downtown Oakland, and perhaps

another one to address the small scale of the towns to the north along San Pablo Bay. One

might speculate that six development types along 25 miles would be incredibly homogenous,

but this is where the fragmented nature of the corridor works its magic! Along the 25 miles,

there are nine cities and four unincorporated towns, lots of rolling topography, and at least 15

creek drainages that cross the avenue. The landscape sets up a rhythm with the high/low views

and the intermittent riparian right-of-ways, while communities create melodies with their

buildings and streetscapes. Perceptually, it creates a continuous corridor, albeit pieced together

incrementally.

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TEST SITES & PHOTO/SECTION MARKERS

X

A

B

B

CC

DD

E

E

F

F

G

G

H

H

J

J

I

I

A

X

Fairmount AveCentral Ave

Moeser Lane

Solano Ave

I-80I-580

Potrero Ave

Cutting Blvd

Macdonald Ave

Barrett Ave

Cross-section, street-view and code test site locations.

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LOOKING NORTH LOOKING SOUTH

A-A

B-B

C-C

D-D

E-EStreet views

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LOOKING NORTH LOOKING SOUTH

F-F

G-G

H-H

I-I

J-JStreet views

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Block Layout

Block layout is necessary for parcels in SPA4 and other areas, such as large strip malls over

50,000 square feet. The perimeter maximum of 1000 feet is about half the length of other

blocks along the 5-mile strip, but the size is meant to promote high pedestrian and bicycle

connectivity in the transit-oriented areas. As an example, block perimeters in downtown

Portland, a very pedestrian-friendly city, are 800 feet in length, or 200 feet square.

Urban Ecotone Code: General Requirements

Parcel Layout

The parcel maximum was intended only for areas where new parcels and blocks needed to be

laid out, but all of the code testers with sites over 20,000sf applied it to their site. For parcels

along San Pablo Avenue in Alameda County, the average area is 8115sf. For parcels along the

avenue in Contra Costa County, the average area is 14,585sf, reflecting the larger number of

strip malls and big box retailers mixed in with the historically platted 50’x100’ (5000sf ) parcel.

Parcel size is important as a scale factor in pedestrian comfort. The 5000sf parcel is a pedestrian-

scaled parcel, but the development of small parcels is typically hindered by costs due to parking

requirements and return on investments percentages. Limiting parcels to 20,000sf in this

thesis is a negotiation between the cultural landscape and the economics of development. The

code test, which I designed for a portion of SPA4, discusses another concession made for this

development type, with respect to block configuration and parcel size.

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Frontage

The requirement for a vertical delineation/differentiation every 50 feet of frontage originates

from the historic 50-foot parcel delineation, which contributes to the cultural landscape of

the corridor. Neoliberal urbanism trends towards parcel assembly for global corporate dollar

development. The densities in Asia, upwards of 500 units per acre, can support this scale

of development where the street becomes a secondary space, but with densities between 40

and 100 units per acre on San Pablo Avenue, the street remains the primary public space and

should be designed to a pedestrian scale (MVRDV 1998).

The frontage requirements assume there are no ground floor residential uses along the avenue.

Perhaps this is a mistake… so this standard will require adjustment in the setbacks and so

forth, most likely in SPA1 and SPA4. There are many different ways to create a semi-public or

transitional zone between the public space of the urban arterial and the private space of ground

floor residential. As an example, the neighborhood district Amsterdam Zuid designed by H.P.

Berlage employs two common tactics: the raised first floor and the recessed entrance.

Public/Private Transition Zone, Amsterdam Zuid 2009.

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Minimum Requirements Diagram

The minimum requirements diagram presents the graphic standard for the development types

by illustrating the basic minimum requirement information and the terms. It is essentially the

same requirements as SPA1, but the massing is configured differently to show variation.


Sustainable Design

The LEED and SSI requirements encompass almost all of the performance standards that

support the urban ecotone concept. As a side note, if all of the buildings were to be LEED

certified, there would be no smoking allowed within 25 feet of any building on San Pablo

Avenue, so smokers would be relegated to the medians. This could be a fun little design project.

These performance standards along with the Seattle Green Factor ordinance upon which the

vegetation standard was based, represent a sustainable building approach where human and

natural ecologies can co-exist in urban conditions. These standards would be incorporated

into the municipalities’ ordinances, therefore codifying these performance standards into the

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landscape. In terms of code administration, projects would need to submit their LEED project

registration receipt and a preliminary checklist indicating which level of LEED the project is

pursuing. These would be submitted along with the checklist for the administrative review

prior to permit approval.


On-Site Energy Production

Returning to the concept of legibility, the more evident the production of energy is reflected

in the landscape, the greater consciousness about energy production will exist, ie. reducing

fossil fuel dependence. This educative philosophy is what fortified the urban creek day-lighting

movement, so why can’t it do the same for other natural factors? On-site energy production

reduces the impacts on existing infrastructure and discounts one of the stated cost barriers to

infill development. Although the upfront costs of energy generation systems are significant,

programs like Berkeley’s FIRST program (Financing Initiative for Renewable and Solar

Technology) provides incentives for decentralized energy production. The largest potential

for district utilities exists in the SPA4 areas, where infrastructure impacts could even reduce

adjacent impacts.

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House the People

It’s a simple idea: passive heating and cooling. In this climate, all a space needs to acclimate to

the comfort zone are two exposures for ventilation and access to sunlight and shade. Solar hot

water heaters can assist heating requirements through radiant heating, but with climate change,

it will only get warmer in the Bay Area. Just say no to the double-loaded corridor! This is the

only country in the world where this economically driven building typology dominates the

landscape, despite the Mediterranean climate indicators for a more efficient type that relies on

passive, cost-free systems.

Feed the People

Urban agriculture is all the rage, so why not codify it? Vancouver is doing it! Out of all the re-

localization issues, food security seems to be paramount. Not only is local food production an

educational landscape, it addresses an environmental justice issue: access to healthy, fresh food.

The current economic recession makes the case for codifying space for urban agriculture even

more poignant as the food banks are reporting shortages and a 30% increase in demand (New

York Times “Newly Poor Swell Lines at Food Banks” February 20, 2009).

Building & Land Use: Existing and Future

This standard pushes the limits of governance in order to test how existing auto-oriented uses

can work with other uses on the same parcel, and to see if reuse of the buildings would be

feasible with the increased intensity of use. Obviously, this standard could not be enforced

as an ordinance, but similar effects can be produced through historic district overlays or

designations, or other incentive programs.

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Auto-repair in a mixed use building with residential above, Amsterdam 2009.

Parking

To make parking scarce on an auto-oriented corridor might kill the businesses or it might make

people act more opportunistically. The on-street parking will remain on San Pablo Avenue so

there will always be an image of parking associated within the right-of-way. The goal of this

code is to remove auto-dominated private parcels which, when combined with the on-street

parking, essentially surround the sidewalk pedestrian realm, turning it into an island.

Stacked mechanical parking structures are incredibly efficient at storing cars that are not used

on a daily basis, which is a common condition associated with residential land uses. Decoupling

the parking from the residential units creates a market for other users to lease the spaces when

the demand is not met by the residential uses. This relationship could benefit the auto-oriented

businesses that frequently exploit the on-street parking causing strife with their neighboring

businesses (surveys and interviews). There are numerous possibilities for stacked mechanical

parking structures.

Auto-repair in a mixed use building with residential above, Rotterdam 2009.

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Parking lifts in single-family residences, Amsterdam, 2009.

Parking lift for a single-family house made to look like decking, Amsterdam, 2009.

Parking lifts in muti-family residences are rented out when there is no tenant demand, Berkeley, 2008.

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Structured district parking provides a larger amount of parking for areas where there is an

increased intensity of commercial uses as found in SPA3 and SPA4. The mixing of diverse

land uses implies different schedules of use, which is where a shared-district parking scheme

can maximize the use of the spaces. There can still be plenty of parking available along San

Pablo Avenue, it just won’t be immediately visible and probably not free of charge. The fees

for parking can be negotiated with the businesses through validation programs, which provides

the incentive for people to learn to use the hidden, structured parking.

The open lot park(ing) standard acknowledges that surface lots are sometimes inevitable, such

as loading areas, but that they should contribute to the public realm when vehicles are not

sitting in them. Open lots can be used for markets, stormwater infiltration sites with habitat,

hard courts for play, and so on. Park(ing) Day, started by the San Francisco design collective

Rebar, influenced the formulation of this standard. Park(ing) Day is an annual event that is

a self-organizing collective action where individuals transform on-street parking spaces into

public spaces for people to generate awareness for the value of public space. The open lot

park(ing) standard codifies the collective action of Park(ing) Day into a quotidian event.

Park(ing) Day Event 2008 (Flickr User Justsmartdesign).

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Gas stations in Paris do not dominate urban form. 2008.

Gas stations in Paris are convenient without taking up lots of space. 2008.

Land Use

Almost anything and everything goes; just be sure to mix them together in a way that promotes

the sidewalk as an interactive public space. The San Francisco Eastern Neighborhoods Urban

Mixed Use zone represents a mix of land uses similar to those on San Pablo Avenue and

promotes a pedestrian-based ground floor land use scheme; it was used as a reference for the

Urban Ecotone Code land use chart. The dwelling unit size distribution reflects the types of

families who live along the corridor in the 5-mile strip. The RHNA numbers presented in the

analysis chapter reflect the distribution of the levels of affordability.

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Riparian & Drainage Areas

The creeks and drainage infrastructure are responsible for conveying all of the stormwater in

the East Bay, and all of the stormwater north of Oakland crosses San Pablo Avenue on its way

to the Bay, so how could San Pablo Avenue and the connecting infrastructure create a multi-

functional infrastructure that improves human and natural ecologies? By adding a visible layer

of green infrastructure on the surface there exists the potential to reduce the impacts on the

decaying subsurface pipe infrastructure, while adding numerous benefits to the human and

natural ecologies in the form of pathway connections and habitat corridors. Again, the issue

of legibility that provides an educative landscape, can be a preventive measure for further

environmental impacts. The San Francisco Public Utilities Commission’s Stormwater Design

Guidelines and the New York City High Performance Infrastructure Guidelines are excellent

sources for urban green infrastructure examples. Nature can function well in the urban fabric,

if it has room. The aesthetics between the suburban vegetated swale and urban stormwater

sidewalk planting are different, but the function can be similar. Putting a secondary stormwater

infrastructure on the surface also provides an alternative urban framework to the street grid

where the private and public realms can interconnect. The code designates a 100’ right-of-way

for the green infrastructure above all creek and drainage infrastructure. This is probably too large

for the drainage systems, but is an acceptable width for daylit creeks and can be incorporated

into the Quimby Act open space requirements for the additional population introduced into

the community. The green infrastructure functions can be divided into typologies by the

following parameters: position in the watershed – upper, middle, lower; ownership – public or

private; and direction of flow – along or across a street or parcel. The design proposals for these

conditions are discussed in greater detail in the public realm portion of the code.


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A park along the Promenade Plantee with stormwater infrastructure and riparian habitat that marks a drainage path to the river, Paris 2008.

Sun Slot

This standard addresses the cultural and productive landscape as an ephemeral condition: the

sun. Most buildings along San Pablo Avenue are currently 2 storeys in height. The 30 year-

old Plane trees in Berkeley are one of the favored elements of San Pablo Avenue (interviews

and surveys). The light and microclimate that is produced by the combination of the low

buildings and trees is one of the positive characteristics of the avenue. The relatively consistent

building height also maximizes the solar exposure for rooftop photovoltaic energy generation.

The current zoning allows for at least 4 storeys with a density bonus for affordable housing

pushing buildings up an additional storey. If San Pablo Avenue transformed into a 5 storey

space overnight, the loss of the amount and quality of light would be significant to the avenue

space and the uses behind these buildings. The sun slot standard negotiates between the need

for a more intense development and the preservation of the ephemeral qualities, microclimate

conditions and energy generation potential that are currently valued on the avenue. The

sun slot standard also provides a semi-private open space for residents and food production,

facilitates the ventilation and two-exposure standard, and reinforces the 50 foot parcel rhythm

through its massing.

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This building under construction in early 2009 is located on the southwest corner of Delaware and San Pablo Avenue. (above) If constructed according to the Ecotone Code, it would have two sun slots and a viewshed setback on the 5th floor (below).


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Vegetation & Stormwater

The vegetation and stormwater standards are connected for a reason: they are mutually beneficial

and when they work together, they produce increasing synergy. These are performance standards

that different municipalities have enacted as ordinances and are triggered by building permits.

The vegetation standard in the Urban Ecotone Code is a simplified version of the Seattle

Green Factor ordinance for their neighborhood commercial streets. From the city’s website,

“this program is designed to improve the quantity and quality of planted areas while allowing

greater flexibility for developers and designers to meet open space requirements” (Seattle Green

Factor website). For building permit approval, there must be evidence of a Green Factor score

higher than 0.3. The Seattle Green Factor was modeled after the Berlin Biotope Area Factor,

which is more demanding of replacing vegetation on a parcel. The vegetation standard in the

Urban Ecotone Code, while less prescriptive, is more demanding than either of the existing

ordinances.

The stormwater performance standard uses the San Francisco Public Utilities Commission

cistern calculator to determine the cistern size for each of the parcels. The cistern is sized to

capture 90% or more of the runoff, assuming that a minimum 10% of stormwater will be

absorbed through the vegetation. Building gray water will also be stored in the cistern so

the 90% capacity will hold enough water to irrigate plants, flush toilets and wash clothes, in

addition to any other water demands factored into the spreadsheet. Graywater piping, also

known as Purple Pipes for domestic use is not permitted in all municipalities, so this standard

requires a policy change in addition to the ordinance. Not only does this standard reduce the

impacts on the stormwater infrastructure, it can also save money on utility costs. An article in

the San Francisco Examiner explains how a homeowner in the city collects all of the rainwater

from her 1000sf rooftop to irrigate her plants, which saves her approximately $200 year in

water costs for 12,500 gallons of water (SF Examiner October 9, 2008).

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Museum Quai Branly façade; the Accenture building in the Tolbiac district of Paris, 2008; Buster Simpson’s Belltown cistern (Flickr User Citywalker); Buster Simpson’s Water Glass cistern and Water Table sculpture (Flickr User Citywalker).

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Open Space by Land Use

Lot coverage maximums address issues of health, safety and access by establishing acceptable

minimum standards, but coverage does not differentiate for land use. Multi-family residential

uses require more access to light, air and open space than other uses, primarily based on tenement

laws established in the 19th Century and expanded upon by later laws (http://ci.columbia.

edu/0240s/0243_2/0243_2_s1_2_text.html accessed 20 March 2009).


Development Types: SPA1 to SPA4

The following table presents the existing zoning, densities and allowable building heights for

parcels along San Pablo Avenue in Richmond and El Cerrito, and compares them to the four

development typologies of the Urban Ecotone Code. The building heights, as mentioned

earlier, are similar between the three codes. The Urban Ecotone Code represent heights that

include the affordable housing density bonus while the existing zoning codes do not include

the additional height, so the difference in size between the existing and proposed codes is not

as large as the numbers suggest. The density increases are easily accommodated within the

building height limits; this is clearly demonstrated in the following code test results. The

key difference between the existing and proposed zoning codes is land use association. The

existing codes limit the types of land use, prescribe parking requirements based on singular uses,

and separate public and private functions into different code categories. The Urban Ecotone

Code does not zone by use, does not prescribe singular use parking requirements, nor does it

distinguish between public and private uses in the development realm because these uses can

be mixed in a single structure.

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Table 6. Existing Zoning Codes and the Urban Ecotone Code, Density and Height Comparisons

City/Code Zone/Development Type Dwelling Units/Acre (incentive density)

Height in feet (Conditional Use Permit Height)

El Cerrito Single-Family Residential 10 35’ (40’) max

Multi-Family Residential 21-35 35’ max

Transit Oriented Mixed-Use

35 (70) 35’ (50’) max

Community Commercial 35 (45) 50’ (65’) max

Public/ Semi-public n/a n/a

Open Space Parks and Recreation

n/a n/a

Richmond Single-Family Low Density Residential

11 35’ max

Multi-Family Residential 26 35’ max

Multi-Family High Density Residential

54 45’ max

General Commercial 34 45’ max

Regional Commercial n/a 65’ max

Community and Regional Recreation

n/a n/a

Urban Ecotone Code

SPA 1 40 min 35’ min/max

SPA 2 40 min 35’ min/ 50’max

SPA 3 60 min 35’ min/ 60’ max

SPA 4 100 min 35’ min/ 72’ max

Source: San Pablo Avenue Specific Plan Existing Conditions Report p.9

Along with the graphic code, each development type specifies a series of form and performance

standards specific to each type. These standards include: maximum lot coverage, maximum

height, number of floors, rear setback, sun slot setback, front and rear viewshed setback,

residential density, and waste and recycling requirements. Land use is included, but only in

reference to the list presented in the common code requirements.

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COMPLIES DOES NOT COMPLY N/AContributes to Urban and Natural Ecotones

BLOCK LAYOUT1000' Perimeter maximum for new blocks

PARCEL LAYOUT20 000sf parcel maximum

FRONTAGEPrimary entrance on SPA or other principle street in SPA 4Vertical delineation every 50' of frontageOpenings designed for daylight and ventilation (25% min)80% minimum of façade built to frontage lineNo parking on frontage

SUSTAINABLE DESIGNcomplies with LEED Silver point levelcomplies with Sustainable Sites certification level

ENERGY PRODUCTIONmaximized on-site energy production

HOUSING AIR QUALITYthrough-floor or double exposure units

FOOD SECURITYdesignate food crop space with residential uses

BUILDING REUSEExisting building re-usedExisting use incorporated into new building

BUILDING LAYOUTmaximum coverage not exceeded35' height minimummaximum height not exceeded3 floor minimummaximum number of floors not exceededresidential density minimumsun slot setbackrear property line setbackrear viewshed setbackfront viewshed setbackwaste and recycling

PARKINGResidential stacked parkingStructured parkingOpen lot park(ing)

LAND USEPrimary uses exceed secondary uses

OPEN SPACE coverage or land use ratio applied

RIPARIAN & DRAINAGE AREASno building in 100' buffer zoneproject incorporates riparian area into design

VEGETATION100% of parcel area identified as on-site vegetation

STORMWATER MANAGEMENT100% of stormwater remains on site--cistern accomodated

ADDITIONAL COMMENTS HERE:

Urban Ecotone Code: Code Checklist

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Documents

Code Design - aeg7aeg7.com/assets/spa/07-code design.pdf · thesis is a negotiation between the cultural landscape and the economics of development. The code test, which I designed